Seattle Malaria Clinical Trials Center (Seattle MCTC)

What is Malaria?

1) Infection is transmitted to human when a mosquito injects sporozoites via bite. 2) Sporozoites enter the liver and infect hepatocytes (liver cells). 3) Liver cells rupture, and merozoites are released into the bloodstream. 4) Merozoites produce gametocytes. 5) Transmission to mosquito (ingests gametocytes via bite).

Graphic by Fred Hutch

World Health Organization reports that about 3.2 billion people – almost half the world’s population – are at risk of malaria. Malaria is a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito which feeds on humans. People who get malaria are typically very sick with high fevers, shaking chills, and flu‐like illness. Five kinds of malaria parasites can infect humans: Plasmodium falciparum, P. vivax, P. ovale, P. knolesi, and P. malariae. Infection with P. falciparum, if not promptly treated, may lead to death. Although malaria can be a deadly disease, illness and death from malaria can usually be prevented and it is easily treated.

According to the Centers for Disease Control, about 1,500 cases of malaria are diagnosed in the United States each year. The vast majority of cases in the United States are in travelers and immigrants returning from malaria‐risk areas, many from sub‐Saharan Africa and Southern Asia.

The World Health Organization reports that about 3.2 billion people — almost half the world’s population — are at risk of malaria. The latest estimates show there were 214 million cases of malaria in 2015 and 438,000 deaths. Young children, pregnant women and non-immune travelers from malaria-free areas are particularly vulnerable to the disease when they become infected. Because malaria causes so much illness and death, the disease is a great drain on many national economies. Since many countries with malaria are already among the poorer nations, the disease maintains a vicious cycle of disease and poverty.